os/os2: add get_executable_path and get_executable_directory

tests/core/os/os2/path.odin

@@ -0,0 +1,22 @@
+package tests_core_os_os2
+
+import os "core:os/os2"
+import    "core:log"
+import    "core:path/filepath"
+import    "core:testing"
+import    "core:strings"
+
+@(test)
+test_executable :: proc(t: ^testing.T) {
+	path, err := os.get_executable_path(context.allocator)
+	defer delete(path)
+
+	log.infof("executable path: %q", path)
+
+	// NOTE: some sanity checks that should always be the case, at least in the CI.
+
+	testing.expect_value(t, err, nil)
+	testing.expect(t, len(path) > 0)
+	testing.expect(t, filepath.is_abs(path))
+	testing.expectf(t, strings.contains(path, filepath.base(os.args[0])), "expected the executable path to contain the base of os.args[0] which is %q", filepath.base(os.args[0]))
+}